Health condition tests in which electrode patches are utilized exemplified by electrocardiographic (ECG) procedures are frequently run in a series such as four times in eight hours, or every six or eight hours, depending on the medication prescribed. In emergency rooms the tests frequently are conducted in shorter periods such as every half hour since a patient's condition in emergency conditions must be monitored closer, often just to see if the medication is performing its anticipated function. By placing the electrode patches of a test in a series in the same spots as in previous tests reliable readings can be assured. That is, the heart's electrical activity such as is picked up by a given wire lead or channel can be relied upon as having been tested each time in the same spot. Thus if there are any changes in the heart's electrical activity over a period of time in a series of tests, this can be seen when a comparison is made between two or more ECG tests in the series.
In electrocardiographic tests there are, for example, "Q", "R", "S" and "T" waves. If the patient has had or is having a heart attack or other heart problems, the graphic representation reveals the patient's heart condition in one or more of the wave forms being higher or lower than the previous readings. In other words by way of example, a change in amplitude of a wave representing a specific heart condition indicates that a deviation from the norm has or is occurring. If patches placed in a given location in a series of tests are an inch or two away from where the previous patches were located, the amplitude readings for a given wave will be artificial. If a comparison is being made between two different readings in a series, a mislocated patch entails considerable effort and time to determine that the reading is false. Such events result in considerable consternation, waste of time and possible misdiagnoses.
An ECG patch is usually made of flexible plastic material, perfectly round, about the size of a silver dollar, with an electrical connector nipple projecting from a metal button centrally located at its exposed surface for contact with an electrical wire lead of one test channel extending from the test equipment. The underside of the patch is provided with a central annular spongy plastic piece, slightly smaller in diameter than a dime, surrounding the region of the connector button which extends through the patch to permit electrical contact with the person being tested. The spongy annulus contains an electrolyte material, such as in gel form, which contacts a patient's skin for making electrical connection with the patient's skin. The remaining underside of the patch surrounding the spongy annulus has an adhesive surface which permits adherence of the patch to a patient like a protective bandage. The electrical connector button is secured to the patch such as by being riveted thereto from its exposed top surface to the underlying annular sponge material. A direct electrical connection is thereby made between the electrolyte material and the connector button. Thus when the patch is placed over a selected spot in which a test is to be conducted, the connector button makes electrical communication with the patient's skin through the electrolyte. The patch is pressed into position over the spot and held in place by the adhesive portion surrounding the sponge annulus, similar to an adhesive bandage. The patch is thus arranged to be readily removable after a test reading has been taken at the selected spot.